Scientists often publish their research findings with some trepidation. They may wonder if the results will be replicated, and whether the conclusions of their study will have influence on their field. One thing that rarely comes to mind is a concern of being sued in court. But there are examples of scientists coming under legal attack for expressing their data-driven findings. The potential chilling effect of such lawsuits on our modern scientific discourse cannot be ignored, nor should it be tolerated.

In a case reported on in January by STAT News, Harvard researcher Pieter Cohen had to defend himself in US federal court over a study that he had coauthored in the journal Drug Testing and Analysis (Drug Test. Anal. 8, 328–333, 2016). The study had analyzed popular supplements and looked for the presence of β-methylphenylethylamine (BMPEA), a compound that is chemically similar to amphetamines. It found BMPEA in six weight-loss products made by the company Hi-Tech Pharmaceuticals. The paper noted that the safety and efficacy of BMPEA had not been proven in human studies.

Hi-Tech initially sued Cohen and his three study coauthors for $200 million for defamation in 2015. The case was dismissed in Georgia, but the company filed a similar lawsuit against Cohen last April in Massachusetts. The company's lawyers maintained, among other complaints, that BMPEA had been deemed safe in studies conducted by Hi-Tech itself. But a jury was not convinced of the allegations, and Cohen ultimately won the defamation trial in November.

It is worth noting that in the US, plaintiffs who lose lawsuits are not required by default to pay the legal costs of the individuals whom they have sued. As such, scientists who have to defend their science-based statements in court must still pay for legal counsel, even if the claims against them are ultimately not substantiated. In many cases, the institution employing the scientist will provide legal assistance, as was the case for Cohen—but this is not a guarantee. Academics who publish data that may be at odds with the market interests of a company need robust legal protection. A safeguard against the silencing of scientists is vital because the threat of lawsuits persists: Jared Wheat, the owner and CEO of Hi-Tech Pharmaceuticals, told STAT News that he hoped the case would “deter others” from making allegations by letting them know that they can be sued.

Dealing with the litigation can be cumbersome and disruptive. The materials that Cohen had to provide to the court included everything from hundreds of pages of lab notes to his written correspondences with Drug Testing and Analysis and his coauthors. This is time and energy lost to the trial that could have been spent in the lab.

Some scientists have objected to the reach of requests for their documents in lawsuits. In the early 1990s, for example, researcher Paul Fischer and colleagues published findings in the Journal of the American Medical Association that indicated six-year-olds almost universally recognized the cigarette mascot 'Old Joe,' a cartoon camel (JAMA 266, 3145–3148, 1991). The findings became embroiled in a California lawsuit against cigarette-maker R.J. Reynolds over the need to place health warnings on promotional products. Subsequently, the company issued Fischer a subpoena to obtain details from him about the participants in his trial. He refused, citing confidentiality agreements signed with the study participants; the medical school where he worked at the time, however, sought to comply with the Georgia Open Records Act, which aimed to enable public access to official records (Law & Contemp. Probs. 59, 159–167, 1996). Ultimately, Fischer sought separate legal representation and resigned from the institution.

Legal experts note that it is significant that Hi-Tech's defamation lawsuit against Cohen ultimately went before a jury. Most cases alleging defamation are dismissed before that stage. Take, for example, a case in which Nature America (which has since become part of Springer Nature, as has this journal) was sued in 2011 for findings published in a study, funded by the Italian company Chiesi Farmaceutici, that appeared in the Journal of Perinatology. The suit was brought by ONY, a biopharmaceutical company based in New York. Both companies produce surfactants for coating the lung surfaces of premature infants or other patients with respiratory-distress syndrome, and the results of the study asserted that Chiesi's product, Curosurf, performed better in certain tests than ONY's product, Infasurf (J. Perinatol. 33, 119–125, 2013). In the suit, ONY alleged that the findings constituted an injurious falsehood. But a US District Court dismissed the case in 2012, and in 2013, a US Court of Appeals ruled that the results were protected by the First Amendment as free speech.

It is perhaps difficult to know the full scope of how many scientists today face legal threats, because it is not often discussed openly. For this reason, scholars familiar with the 'chilling effect' of lawsuits pertaining to scientific papers have called for more open dialogue and disclosure about such legal action, so that the public is made aware of its influence (PLoS Med. 11, e1001615, 2014).

The future is unclear, and perhaps even more litigious. As this issue of Nature Medicine went to press, many advocates of free speech remained concerned about campaign promises made by US President Donald Trump, who spoke during his 2016 candidacy about changing libel laws to make it easier to sue. It's unclear what precise changes he has in mind, and whether they would have implications for scientific free speech. But what remains certain is that when scientists withhold well-researched findings out of fear of retribution and costly lawsuits, everyone loses. That is a future no one should want.